Only a couple things have really gone wrong. The first is my alternator went, but that will pretty much happen with any car.
My aftermarket (Razzi) ground effects also got smashed up, probably because I lowered the car too much and drove in winter, other than that no big problems.
The 3.1 engine is a great engine.
I have added a Tsudo custom exhaust system, custom ram air (although I'm planning on switching it for a cold air kit), 75shot nex nitrous oxide kit, put on 50 series rubber on the stock rims, Optima battery, Razzi ground efx, custom painted headlight covers, 35% tint, shaved the body molding, and dropped the car a good 2 and a half inches (the 50 series tires left a huge wheel well gap).